Magnetic Compass Orientation in a Palaearctic-Indian Night Migrant, the Red-Headed Bunting.

Red-headed Buntings (Emberiza bruniceps) perform long-distance migrations within their southerly overwintering grounds and breeding areas in the northern hemisphere. Long-distance migration demands essential orientation mechanisms. The earth's magnetic field, celestial cues, and memorization of geographical cues en route provide birds with compass knowledge during migration. Birds were tested during spring migration for orientation under natural clear skies, simulated overcast skies at natural day length and temperature, simulated overcast at 22 °C and 38 °C temperatures, and in the deflected (-120°) magnetic field. Under clear skies, the Red-headed Buntings were oriented NNW (north-northwest); simulated overcast testing resulted in a northerly mean direction at local temperatures as well as at 22 °C and 38 °C. The Buntings reacted strongly in favor of the rotated magnetic field under the simulated overcast sky, demonstrating the use of a magnetic compass for migrating in a specific direction.

Frequency estimation techniques in capacitance-to-frequency conversion measurement.

The process of capacitance measurement consists of converting the capacitance under measurement into a secondary variable such as voltage, time-period, and frequency. This paper lays special focus on the capacitance-frequency measurement due to the offered advantages by this technique over the other methods. For this purpose, a review of the various frequency estimation techniques is presented while exploring the possibility of applying them for capacitance measurement. These techniques are mainly classified as phase-locked loop, frequency-locked loop (FLL), parameter estimation methods, and discrete Fourier transform (DFT) based FLL structures. Furthermore, the possibility of integrating computationally efficient DFT structures in frequency locked loops has been investigated. The performance comparison of these techniques proves that a more accurate measurement of capacitance could be achieved through them. The proposed methodology of capacitance measurement offers good accuracy, wider range, quick convergence, and system-on-chip implementation. Moreover, FLLs could be applied for the capacitance measurement when the input signal is nonsinusoidal.

Evaluation, comparison of different solvent extraction, cell disruption methods and hydrothermal liquefaction of Oedogonium macroalgae for biofuel production.

Cell disruption and lipid extraction methods for macroalgae are not well reported. Therefore, we compared various lipid extraction methods and extraction efficiency of various solvents to improve lipid yields from Oedogonium fresh water macroalgae. Lipid extraction was done by 2 methods viz., modified Bligh and Dyer method and soxhlet extraction using either single solvents or mixtures. In soxhlet extraction method five solvents were used (1) Hexane commonly used solvent for lipid extractions, (2) chloroform: methanol (2:1), (3) Chloroform: hexane (1:1), (4) Chloroform: hexane (1:2), (5) Dichloromethane + methanol (2:1). To improve lipid extraction yields, various cell disruption methods were also compared during the present study. Impurities of chlorophyll and protein were also detected in the extracted lipids. Hydrothermal liquefaction of algal biomass with TiO2 was also conducted at 300 °C. HTL was more effective by which 23.3 wt% of bio-crude oil was obtained.